Method of building tunnels



Patentd Dec. 1, 1885.

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(No Model.)

o. SOQYSMITH. METHOD OF BUILDING TUNNELS.

UNITED STATES CHARLES SOOYSMITH, OF CHICAGO, ILLINOIS.

METHOD OF BUILDING TUNNELS.

SJ'PECIFICATION forming part of Letters Patent No. 331,657, datedDecember l, 1885.

Serial No. 153,103. (No model.)

.To all whom, it may concern.-

Beit known that I, CHARLES SooYsMrTH, a citizen of the United States,residing at Chi cago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Methods of BuildingTunnels, &c., of which the following is a specification, reference beinghad therein to the accompanying drawings.

This invention relates to animproved method of building tunnels andother engineering operations; and the invention consists in the novelapplication of a freezing method for closing the joints between thebottom edge of caissons or of coffer-dams and the bottom or the bed-rockof rivers, harbors, tc., or for closing the joints between caissons sunkend to end to form a continuous passage wherein a tunnel may be built.

My invention consists, also, in the novel manner of placingfreezing-pipes (containing a circulating freezing-mixture) under theedge or adjacent to the edge of caissons, cofferdams, dre., luting orpacking mud, clay, or other substances of this nature against said pipesand edges, causing said mud, clay, tc., to congeal and adhere to thebottom of the caisson or of the coder-dams and to its support, andsolidly unite the parts, all as hereinafter more particularly described,and specically set forth in the claim.

In the accompanying drawings, Figure l is a transverse vertical sectionof a caisson sunk into the bottom of a river, harbor, 35e. Fig. 2 is atransverse vertical section of a cofferdam provided with means to packitsv lower edge and freeze the packing. Fig. 3 is an end elevation of acaisson provided with my improvement. Fig. 4L is a side elevation of oneend of two contiguous caissons provided with freezing-pipes around theiredges.

Like letters indicate like parts in all the gures.

In Fig. l, A represents the walls of a caisson loaded with masonry B,through the center of which there is ahollow shaft, b, provided with theusual air-lock, b2, for the passage of the workmen into the air-chamberA", inclosed by the walls A. The caisson is represented as having beensunk through a body of water, C, and alluvial or other soil, G2, untilarrested by the bed-rock or solid material D, into which a certainamount of excavation and leveling is to be done.

To prevent water from entering into the airchamber between the loweredges of its walls and the inequalities in the surface of the bedrockwithout maintaining a very heavy airpressure in the air-chamber, mymethod is to seal the lower portion of the walls of the caisson to thebedrock, as follows: I secure to the under edge of the walls A freezing-pipes a, preferably in grooves formed for their protection, and I packin close contact to the pipes a, a sufficient amount of luting material,c, containing some water in suspension-such as mud, damp clay, Src-andcause a current of refrigerating gas or liquid to circulate through thepipes c. The packed mud e rapidly becomesa frozen mass, that adheresrmly to the walls A and their supporting material D, and the smallamount of water imprisoned between the lower portion of the walls A andthe soil G2 becomes also frozen, and forms an additional seal againstthe en trance of water in the air-chamber. The freezing-pipes c areplaced preferably against or close to the outside of the walls A, sothat when the excavation is continued under the air chamber there willremain a sufficient quantity of frozen material under the walls A. Thesame method is shown in Fig. 2 as applied to a coffer-dam, the walls ofwhich are shown at A2, and resting partly upon the bed-rock D. The loweredge of the walls is provided with one or more freezing-pipes, a, and asuiifcient quantity of lute, as mud e or other suitable materialcontaining water in suspension, is packed under and around the loweredge of the coffendam, and as soon as the refrigerating materialcirculates through the pipes a the water in the mud e becomes congealedand sufciently seals the lower edge of the coffer-dam against theadmission of water.

To build tunnels under water it has been proposed to sink caissons endto end in the position desired for the tunnel, each chamber being largeenough to build a section of the tunnel. These chambers were to beclosed at the end by bulk-heads that could be removed to connectadjacent caissons. The difficulty has been to bring the adjacentcaissons close enough or their line of j unction tight enough to preventthe entrance of water in the tunnel IOO after the buik-head or ends wereremoved. By my method Ythis difficulty is removed.

To the ends of the caissons, and close to their outer edges, are securedone or more freezingpipes, a, as shown in Fig. 3. rEhe ends of thecaissons are then brought at a short distance from each other, as shownin Fig. 4, and the Space between them filled with luting mud, clay,Ste., and frozen by the circulating medium passing through thefreezing-pipes. The bulk-heads can then be removed and the space for thetunnel cut from the frozen material and the tunnel built in theinterior, the pipes a being far enough out to permit this Withoutdisturbing them. l

Having now fully described my invention,

CHARLES SOOYSMITH.

Witnesses:

PHILIP MAURO, E. E. MAssoN.

